android之清理缓存实现，供大家参考，具体内容如下

一. 清理缓存首先要搞清楚清理哪些东西

1、app本身的功能比如录像,录音,更新都会产生文件,需要清理
2、app的默认缓存地址cache

二. 搞清楚要清理的文件夹位置

1、首先app自身的功能就要看自己把它放在了什么位置
2、默认缓存地址:getActivity().getExternalCacheDir();
这个位置是在storage/emulated/0/Android/data/com.xxxxxapp/cache

三.代码功能模块:

1、获取app缓存大小,以字节为单位
2、获取某个文件夹的大小,以字节为单位
3、把字节单位换算成常用单位
4、把缓存大小设置到页面,清理前一次,清理后一次
5、删除文件夹功能
6、清除app缓存

/**
 * 获取app的缓存大小
 * 1. 录制的视频/storage/emulated/0/xueliangapp/video/1573972925136.mp4
 * 2. 录制的音频/storage/emulated/0/xueliangapp/radio/1573972925136.amr
 * 3. 下载的更新包/storage/emulated/0/Android/data/com.sdxzt.xueliangapp_v3/files/Download/xueliang_update.apk
 * 4. 缓存/storage/emulated/0/Android/data/com.sdxzt.xueliangapp_v3/cache
*/
  File videoDir,radioDir,filesDir,cacheDir;
  private String getAppCache(){
    long fileSize = 0;
    String cacheSize = "0KB";
    videoDir = new File(Environment.getExternalStorageDirectory()+"/xueliangapp/video");
    Log.d(TAG,"getAppCache: videoDir大小: "+getDirSize(videoDir));
    radioDir = new File(Environment.getExternalStorageDirectory()+"/xueliangapp/radio");
    Log.d(TAG,"getAppCache: radioDir大小: "+getDirSize(radioDir));
    filesDir = getActivity().getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS);
    Log.d(TAG,"getAppCache: filesDir大小: "+getDirSize(filesDir));
    ///storage/emulated/0/Android/data/com.sdxzt.xueliangapp_v3/files,这里面有download文件夹,里面是下载的更新包
    cacheDir = getActivity().getExternalCacheDir();
    Log.d(TAG,"getAppCache: cacheDir大小: "+getDirSize(cacheDir));
    ///storage/emulated/0/Android/data/com.sdxzt.xueliangapp_v3/cache
    fileSize += getDirSize(getActivity().getFilesDir());
    fileSize += getDirSize(getActivity().getCacheDir());//这行是默认的缓存地址,看图片什么的会在这里积累缓存
    fileSize += getDirSize(videoDir);
    fileSize += getDirSize(radioDir);
    fileSize += getDirSize(filesDir);
    fileSize += getDirSize(cacheDir);
    String fileSizeStr = formatFileSize(fileSize);
    Log.d(TAG,"getAppCache: 总缓存大小: "+fileSizeStr);
    return fileSizeStr;
  }

  /**
   * 获取文件大小(字节为单位)
   * @param dir
   * @return
   */
  private long getDirSize(File dir) {
    if (dir == null) {
      return 0;
    }
    if (!dir.isDirectory()) {
      return 0;
    }
    long dirSize = 0;
    File[] files = dir.listFiles();
    for (File file : files) {
      if (file.isFile()) {
        dirSize += file.length();//文件的长度就是文件的大小
      } else if (file.isDirectory()) {
        dirSize += file.length();
        dirSize += getDirSize(file); // 递归调用继续统计
      }
    }
    return dirSize;
  }

  /**
   * 格式化文件长度
   * @param fileSize
   * @return
   */
  private String formatFileSize(long fileSize){
    DecimalFormat df = new DecimalFormat("#0.00");//表示小数点前至少一位,0也会显示,后保留两位

    String fileSizeString = "";
    if (fileSize < 1024) {
      fileSizeString = df.format((double) fileSize) + "B";
    } else if (fileSize < 1048576) {
      fileSizeString = df.format((double) fileSize / 1024) + "KB";
    } else if (fileSize < 1073741824) {
      fileSizeString = df.format((double) fileSize / 1048576) + "MB";
    } else {
      fileSizeString = df.format((double) fileSize / 1073741824) + "G";
    }
    return fileSizeString;
  }
  private void setAppCache() {
    String fileSize = getAppCache();
    fileSizeTv.setText(fileSize);
    Log.d(TAG,"setAppCache: 重新显示缓存大小");
    Log.d(TAG,"setAppCache: 当前缓存"+fileSize);
  }

  public void clearAppCache(final Activity activity){

    final Handler handler = new Handler(){
      @Override
      public void handleMessage(@NonNull Message msg) {
        super.handleMessage(msg);
        Log.d(TAG,"handlerMessage: ");
        if (msg.what == 1) {
          setAppCache();
          Log.d(TAG,"handlerMessage: 缓存清除完毕");
          ToastUtil.showMsg(getActivity(),"缓存清除完毕");
        }else {
          ToastUtil.showMsg(getActivity(),"缓存清除失败");
          Log.d(TAG,"handlerMessage: 缓存清除失败");
        }
      }
    };

    new Thread(new Runnable() {
      @Override
      public void run() {
        Log.d(TAG,"run: ");
        Message msg = new Message();
        try {
          clearCacheFolder(videoDir,System.currentTimeMillis());
          clearCacheFolder(radioDir,System.currentTimeMillis());
          clearCacheFolder(filesDir,System.currentTimeMillis());
          clearCacheFolder(cacheDir,System.currentTimeMillis());
          msg.what = 1;
        }catch (Exception e){
          e.printStackTrace();
          msg.what = -1;
        }
        handler.sendMessage(msg);
      }
    }).start();
  }

  /**
   * 清除缓存目录
   * @param dir 目录
   * @param curTime 当前系统时间
   */
  private int clearCacheFolder(File dir,long curTime){
    int deletedFiles = 0;
    if (dir!= null && dir.isDirectory()) {
      try {
        for (File child:dir.listFiles()) {
          if (child.isDirectory()) {
            deletedFiles += clearCacheFolder(child,curTime);
          }
          if (child.lastModified() < curTime) {
            if (child.delete()) {
              deletedFiles++;
            }
          }
        }
      } catch(Exception e) {
        e.printStackTrace();
      }
    }
    Log.d(TAG,"clearCacheFolder: 清除目录: "+dir.getAbsolutePath());
    return deletedFiles;
 }

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持我们。